Method of fabricating light emitting devices

ABSTRACT

A manufacturing apparatus is provided, which can improve a utilization efficiency of an evaporation material, reduce manufacturing costs of a light emitting device having an organic light emitting element, and shorten manufacturing time necessary to manufacture a light emitting device. According to the present invention, a multi-chamber manufacturing apparatus having plural film forming chambers includes a first film forming chamber for subjecting a first substrate to evaporation and a second film forming chamber for subjecting a second substrate to evaporation. In each film forming chamber, plural organic compound layers are laminated, thereby improving the throughput. Further, it is possible that the respective substrates in the plural film forming chambers are subjected to evaporation in the same manner in parallel, while another film forming chamber undergoes cleaning.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a manufacturing apparatus used for filmformation of a material that can be formed into a film by evaporation(hereinafter referred to as evaporation material) and a manufacturingmethod of a light emitting device typified by an EL element. Inparticular, the present invention relates to a technique using anorganic material as the evaporation material and being effective whenmanufacturing a light emitting device. Note that the term “lightemitting device” in this specification refers to an image displaydevice, a light emitting device, or a light source (includingilluminating devices). Also included in the definition of the lightemitting device are: a module in which a connector such as an FPC(flexible printed circuit), a TAB (tape automated bonding) tape, or aTCP (tape carrier package) is attached to a light emitting device; amodule in which a printed wiring board is provided on the tip of a TABtape or a TCP; and a module in which an IC (integrated circuit) ismounted directly to a light emitting element by a COG (chip on glass)method.

2. Description of the Related Art

In recent years, the research of light emitting devices using an ELelement as a self-luminous element has become active. In particular,light emitting devices using an organic material as an EL material areattracting more attention. The light emitting devices are called organicEL displays (OELD) or organic light emitting diodes (OLED).

Note that an EL element has a layer (hereinafter referred to as ELlayer) containing an organic compound in which luminescence developed byapplying an electric field (electroluminescence) is obtained, an anode,and a cathode. The types of the organic compound luminescence includeslight emission when returning from a singlet excitation state to aground state (fluorescence) and light emission when returning from atriplet excitation state to a ground state (phosphorescence). Both typesof light emission can be applied to a light emitting device produced bya film forming apparatus and a film formation method according to thepresent invention.

Unlike liquid crystal display devices, light emitting devices are of aself-luminous type, thereby causing no problem of a view angle. Morespecifically, the light emitting devices are more suitable as a displayused outside than the liquid crystal displays. Thus, the use of thelight emitting devices in various forms has been proposed.

An EL element has a structure in which an EL layer is sandwiched betweena pair of electrodes, and the EL layer normally has a laminatestructure. A typical example of the laminate structure is one composedof “a hole transporting layer/a light emitting layer/and an electrontransporting layer”. Most of the light emitting devices currently underresearch and development adopt the structure due to its extremely highlight emitting efficiency.

Alternatively, another laminate structure may be used in which: a holeinjecting layer, a hole transporting layer, a light emitting layer, andan electron transporting layer are laminated onto an anode in the statedorder; or a hole injecting layer, a hole transporting layer, a lightemitting layer, an electron transporting layer, and an electroninjecting layer are laminated onto an anode in the stated order.Fluorescent pigments and the like may also be doped into the lightemitting layers. Further, all of the above layers may be formed usingonly low-molecular weight materials, or may be formed using onlyhigh-molecular weight materials.

Further, EL materials used to form an EL layer are broadly divided intolow-molecular weight (monomer-based) materials and high-molecular weight(polymer-based) materials, while the low-molecular weight materials areformed into films mainly by evaporation.

The EL material is extremely likely to deteriorate, because the ELmaterial is easily oxidized due to presence of oxygen or moisture. Thus,a photolithography step cannot be performed after film formation. Inorder to form a pattern, it is necessary to use a mask (hereinafterreferred to as evaporation mask) having an opening portion to separateout the pattern region at the same time of the film formation.Therefore, most of the sublimated organic EL materials are adhered to aninner wall of a film forming chamber or an adhesion proof shield(protective plate for preventing an evaporation material from adheringto the inner wall of the film forming chamber). As a result, anevaporation apparatus needs regular maintenance such as a cleaningprocess for removing adhered substances from the inner wall of the filmforming chamber and the adhesion proof shield, thereby making itinevitable to temporarily stop a manufacturing line for mass productionduring the maintenance.

In order to improve uniformity of a film thickness, conventionalevaporation apparatuses have a larger interval between a substrate andan evaporation source, so that the apparatuses per se have a largersize. Also, the conventional evaporation apparatuses have a structure,as shown in FIG. 22, in which the interval between a substrate and anevaporation source is set to 1 m or more and the substrate is rotated toobtain a film having a uniform thickness. Further, the evaporationapparatuses have such a structure as to rotate the substrate, so thatthere is a limitation on an evaporation apparatus for attaining alarge-area substrate. Also, the interval between a substrate and anevaporation source is large, so that a speed of film formation isreduced and a longer time is necessary to exhaust a film formingchamber, thereby reducing the throughput.

In addition, in the conventional evaporation apparatuses, theutilization efficiency of an expensive EL material is as extremely lowas approximately 1% or low. Thus, the manufacturing costs of a lightemitting device are extremely high.

An EL material is extremely expensive and costs higher per gram thangold costs per gram. Therefore it is desired to use an EL material asefficiently as possible. However, in the conventional evaporationapparatuses, the utilization efficiency of the expensive EL material islow.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above, and thereforehas an object to provide an evaporation apparatus and a manufacturingapparatus, which are capable of improving a utilization efficiency of anEL material, excellent in uniformity, and excellent in throughput.

Due to evaporation being performed in vacuum, it takes a long time toset an inside of a film forming chamber to vacuum and a time necessaryfor each step differs in every film forming chamber. Thus, it isdifficult to design manufacturing processes as automated steps, therebyputting a limitation on improvement in productivity. In particular, ittakes a long time to deposit and laminate layers containing an organiccompound by evaporation, so that there is a limitation on reduction in aprocessing time per substrate. In view of the above, the presentinvention has another object to reduce a processing time per substrate.

Further, another object of the present invention is to provide amanufacturing apparatus capable of maintenance of a film forming chamberwithout temporarily stopping a manufacturing line.

Further, according to the present invention, there is provided a methodof depositing an EL material by evaporation efficiently on a large-areasubstrate having a size such as 320 mm×400 mm, 370 mm×470 mm, 550 mm×650mm, 600 mm×720 mm, 680 mm×880 mm, 1000 mm×1200 mm, 1100 mm×1250 mm, or1150 mm×1300 mm.

Further, according to the present invention, there is provided amanufacturing system capable of preventing impurities from mixing intoan EL material.

According to the present invention, there is provided a multi-chambermanufacturing apparatus having plural film forming chambers, including afirst film forming chamber for subjecting a first substrate toevaporation and a second film forming chamber for subjecting a secondsubstrate to evaporation, characterized in that plural organic compoundlayers are laminated in respective film forming chambers in parallel,thereby reducing a processing time per substrate. More specifically,after the first substrate is loaded from a transfer chamber into thefirst film forming chamber, a surface of the first substrate issubjected to evaporation, while after the second substrate is loadedfrom the transfer chamber into the second film forming chamber, asurface of the second substrate is also subjected to evaporation. InFIG. 1, four film forming chambers are connected to a transfer chamber102. Therefore, as shown in FIG. 6A showing an example of a sequencefrom loading of substrates to unloading of the substrates, it ispossible that four substrates are loaded into the respective filmforming chambers and sequentially subjected to evaporation in parallel.

According to the present invention, in order to maintain uniform cycletimes during mass production, plural chambers are provided at least asevaporation chambers and heating chambers, and a single chamber may beprovided as another chamber having a relatively short processing time.Accordingly, the present invention allows efficient mass production.

According to a first structure of the present invention disclosed inthis specification, there is provided a manufacturing apparatus,including:

a load chamber;

a transfer chamber that is connected to the load chamber; and

plural film forming chambers that are connected to the transfer chamber,wherein:

the plural film forming chambers are each connected to a vacuum-exhaustprocess chamber for setting an inside of the film forming chamber tovacuum, and each include: alignment means for performing positionalignment of a mask and a substrate; an evaporation source; and meansfor heating the evaporation source; and

in at least two of the plural film forming chambers, surfaces ofsubstrates loaded into the respective film forming chambers aresubjected to evaporation in parallel.

Further, not only the film forming chambers in which an organic compoundlayer is formed but also the film forming chambers, sealing chambers,and pretreatment chambers in which electrodes (cathodes or anodes) areformed on the organic compound layer may be provided in plural number,respectively, and the respective forming processes may be performed inparallel similarly. Therefore, according to a second structure of thepresent invention disclosed in this specification, there is provided amanufacturing apparatus, including:

a load chamber;

a transfer chamber that is connected to the load chamber;

plural film forming chambers that are connected to the transfer chamber,and

plural sealing chambers, wherein:

the plural film forming chambers are each connected to a vacuum-exhaustprocess chamber for setting an inside of the film forming chamber tovacuum, and each include: alignment means for performing positionalignment of a mask and a substrate; an evaporation source; and meansfor heating the evaporation source;

in at least two of the plural film forming chambers, surfaces ofsubstrates loaded into the respective film forming chambers aresubjected to evaporation in parallel; and

each substrate is assigned to one of the plural sealing chambers to besealed therein.

Further, according to the present invention, even though the processingnumber of substrates is slightly reduced, the effective evaporationprocess can be realized. For example, as shown in FIG. 6B showing anexample of a sequence from loading of substrates to unloading of thesubstrates, even when a fourth film forming chamber is undergoing themaintenance, evaporation can be performed in first to third film formingchambers sequentially without temporarily stopping the production line.Therefore, according to a third structure of the present inventiondisclosed in this specification, there is provided a manufacturingapparatus, including:

a load chamber;

a transfer chamber that is connected to the load chamber; and

plural film forming chambers that are connected to the transfer chamber,wherein:

the plural film forming chambers are each connected to a vacuum-exhaustprocess chamber for setting an inside of the film forming chamber tovacuum, and each include: alignment means for performing positionalignment of a mask and a substrate; an evaporation source; and meansfor heating the evaporation source; and

in at least two of the plural film forming chambers, surfaces ofsubstrates loaded into the respective film forming chambers aresubjected to evaporation in parallel, and in at least one of the pluralfilm forming chambers, the inside of the film forming chamber undergoescleaning.

Further, in the case of forming a single-color light emitting device, asshown in FIG. 2A showing a sequence from loading of substrates tounloading of the substrates, a hole transporting layer (referred to asHTL), a light emitting layer, and an electron transporting layer(referred to as ETL) are continuously laminated in the same film formingchamber, thereby improving the throughput. When the hole transportinglayer, the light emitting layer, and the electron transporting layer arecontinuously laminated in the same film forming chamber, as shown inFIGS. 9A and 9B, plural evaporation source holders (evaporation sourceholders each moving in the direction X or in the direction Y) may beprovided in one film forming chamber. By using an evaporation apparatusin FIGS. 9A and 9B, a utilization efficiency of an evaporation materialcan be improved.

The respective structures described above are characterized in that inat least two of the plural film forming chambers, evaporation processesof layers containing the same organic compound are performed inparallel.

Further, as shown in FIG. 6A showing an example of a sequence fromloading of substrates to unloading of the substrates, a transfer pathfor a substrate is divided into the same number of paths as that of thefilm forming chambers arranged in connection to each transfer chamber,so that film formation can be efficiently performed in order. Note thatan example of the path for one substrate from loading of substrates tounloading of the substrates is shown by the arrows in FIG. 3. Therefore,according to a fourth structure of the present invention disclosed inthis specification, there is provided a manufacturing apparatus,including:

a load chamber;

a transfer chamber that is connected to the load chamber; and

plural film forming chambers that are connected to the transfer chamber,wherein:

the plural film forming chambers are each connected to a vacuum-exhaustprocess chamber for setting an inside of the film forming chamber tovacuum, and each include: alignment means for performing positionalignment of a mask and a substrate; an evaporation source; and meansfor heating the evaporation source; and

plural substrates loaded into the load chamber are each assigned to oneof the plural film forming chambers in the transfer chamber to be loadedthereinto, and each substrate undergoes processes along one of differentpaths whose number is the same as that of the film forming chambers.

Further, in the case of forming a full-color light emitting device, asshown in FIG. 2B, a hole transporting layer, a light emitting layer, andan electron transporting layer may preferably be continuously laminatedin the same film forming chamber. When the hole transporting layer, thelight emitting layer, and the electron transporting layer arecontinuously laminated in the same film forming chamber, there may beused such a film forming apparatus as shown in FIGS. 9A and 9B, that is,an evaporation apparatus provided with plural, at least three or more,evaporation source holders (evaporation source holders each moving inthe direction X or in the direction Y) in one film forming chamber. Notethat as shown in FIG. 4 showing a sequence from loading of substrates tounloading of the substrates, all the necessary organic layers, forexample, the hole transporting layer, the light emitting layer, and theelectron transporting layer may continuously be laminated in differentthree film forming chambers (a film forming chamber for a red lightemitting element, a film forming chamber for a blue light emittingelement, and a film forming chamber for a green light emitting element).For example, the hole transporting layer, the light emitting layer, andthe electron transporting layer which are to compose a red lightemitting element are selectively laminated by using an evaporation mask(R) in a first chamber; the hole transporting layer, the light emittinglayer, and the electron transporting layer which are to compose a bluelight emitting element are selectively laminated by using an evaporationmask (B) in a second chamber; and the hole transporting layer, the lightemitting layer, and the electron transporting layer which are to composea green light emitting element are selectively laminated by using anevaporation mask (G) in a third chamber, thereby realizing full-colordisplay. Note that in FIG. 4, mask alignment is performed beforeevaporation in each chamber to perform film formation in a predeterminedregion.

Further, in the case where the hole transporting layer, the lightemitting layer, and the electron transporting layer are laminated in onechamber, in order to realize the full-color display, for example,materials (organic materials to become the hole transporting layer andthe electron transporting layer) optimum for a given color (R, G, or B)can be selected appropriately. The feature of the present invention alsoresides in that the film thicknesses of those layers can be changed inaccordance with colors. Therefore, different materials can be used forall the nine types of layers in total: the hole transporting layer, thelight emitting layer, and the electron transporting layer for R; thehole transporting layer, the light emitting layer, and the electrontransporting layer for G; and the hole transporting layer, the lightemitting layer, and the electron transporting layer for B. Note thatorganic materials to become the hole transporting layer or the electrontransporting layer may be used as the common materials.

Further, in the case where the hole transporting layers, the lightemitting layers, and the electron transporting layers for R, G, and Bare laminated in the different three film forming chambers, an exampleof the path for one substrate is shown simply by the arrows in FIG. 5.For example, after a first substrate is loaded into a first film formingchamber, a layer containing an organic compound for red light emissionis formed into a laminate film, and then the first substrate isunloaded. Subsequently, after the first substrate is loaded into asecond film forming chamber, a layer containing an organic compound forgreen light emission is formed into a laminate film, while after asecond substrate is loaded into the first film forming chamber, a layercontaining an organic compound for red light emission may be laminatedto the second substrate to form a film. Lastly, after the firstsubstrate is loaded into a third film forming chamber, a layercontaining an organic compound for blue light emission is formed into alaminate film, while after the second substrate is loaded into thesecond film forming chamber, a third substrate is loaded into the firstfilm forming chamber, and layers may sequentially be laminated to therespective substrates.

Further, the present invention is not limited to the structure in whichthe hole transporting layer, the light emitting layer, and the electrontransporting layer are continuously laminated in the same chamber.However, the hole transporting layer, the light emitting layer, and theelectron transporting layer may be laminated in plural chambersconnected to each other. For example, the hole transporting layer tocompose a green light emitting element is formed into a film in thefirst chamber, the light emitting layer to compose the green lightemitting element is formed into a film in the second chamber, and theelectron transporting layer to compose the green light emitting elementis formed into a film in the third chamber. Accordingly, the layerscontaining an organic compound for green light emission may be formedinto laminate films.

Further, in the above description, as the typical example of layerscontaining an organic compound arranged in a position between a cathodeand an anode, the laminate structure of the three layers consisting ofthe hole transporting layer, the light emitting layer, and the electrontransporting layer. However, there is no particular limitation thereon.Another laminate structure may be used in which: a hole injecting layer,a hole transporting layer, a light emitting layer, and an electrontransporting layer are laminated onto an anode in the stated order; or ahole injecting layer, a hole transporting layer, a light emitting layer,an electron transporting layer, and an electron injecting layer arelaminated onto an anode in the stated order. Alternatively, a doublelayer structure or a single layer structure may be used. Fluorescentpigments and the like may also be doped into the light emitting layers.Also, examples of the light emitting layers include a light emittinglayer having hole transportability and a light emitting layer havingelectron transportability. Further, all of the above layers may beformed using only low-molecular weight materials, or one or severallayers of the above layers may be formed using high-molecular weightmaterials. Note that in this specification, the layers provided betweenthe cathode and the anode are generically referred to as a layer (ELlayer) containing an organic compound. Therefore, the hole injectinglayer, the hole transporting layer, the light emitting layer, theelectron transporting layer, and the electron injecting layer which aredescribed above are all included in the EL layers. In addition, thelayer (EL layer) containing an organic compound may also contain aninorganic material such as silicon.

Note that a light emitting element (EL element) has a layer (hereinafterreferred to as EL layer) containing an organic compound in whichluminescence developed by applying an electric field(electroluminescence) is obtained, an anode, and a cathode. The types ofthe organic compound luminescence includes light emission when returningfrom a singlet excitation state to a ground state (fluorescence) andlight emission when returning from a triplet excitation state to aground state (phosphorescence). Both types of light emission can beapplied to a light emitting device produced according to the presentinvention.

Further, in the light emitting device according to the presentinvention, there is no particular limitation on a drive method forscreen display. For example, a dot-sequential drive method, aline-sequential drive method, a plane-sequential drive method, and thelike are used. Typically, the line-sequential drive method is used, anda time-division gray scale drive method and an area gray scale drivemethod may also be used appropriately. Also, a picture signal inputtedto a source line of the light emitting device may be an analog signal ormay be a digital signal, so that drive circuits and the like may bedesigned appropriately in accordance with picture signals.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 shows an example of a manufacturing apparatus according toEmbodiment 1 of the present invention;

FIGS. 2A and 2B each show an example of a sequence for the manufacturingapparatus according to Embodiment 1;

FIG. 3 shows an example of a transfer path for a substrate according toEmbodiment 1;

FIG. 4 shows another example of the sequence for the manufacturingapparatus according to Embodiment 1;

FIG. 5 shows an example of the transfer path for a substrate accordingto Embodiment 1;

FIGS. 6A and 6B each show another example of the sequence for themanufacturing apparatus according to Embodiment 1;

FIG. 7 shows an example of a transfer path for two substrates accordingto Embodiment 1;

FIGS. 8A to 8C show an evaporation apparatus according to Embodiment 2of the present invention;

FIGS. 9A and 9B show the evaporation apparatus according to Embodiment 2of the present invention;

FIGS. 10A and 10B show examples of a container according to Embodiment 3of the present invention;

FIGS. 11A and 11B show other examples of the container according toEmbodiment 3 of the present invention;

FIGS. 12A and 12B show examples of an evaporation source holderaccording to Embodiment 3 of the present invention;

FIG. 13 shows a manufacturing system according to Embodiment 4 of thepresent invention;

FIG. 14 shows a transfer container according to Embodiment 4 of thepresent invention;

FIGS. 15A and 15B show an evaporation apparatus according to Embodiment4 of the present invention;

FIGS. 16A and 16B show the evaporation apparatus according to Embodiment4 of the present invention;

FIGS. 17A and 17B show a light emitting device according to Example 1 ofthe present invention;

FIGS. 18A and 18B show the light emitting device according to Example 1of the present invention;

FIGS. 19A to 19C show the light emitting device according to Example 1of the present invention;

FIGS. 20A to 20H each show an example of electronic equipment using thepresent invention;

FIG. 21 shows another example of the manufacturing apparatus accordingto Embodiment 1 of the present invention; and

FIG. 22 shows a conventional evaporation apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EXAMPLES

Hereinafter, embodiments of the present invention will be described.

Embodiment 1

FIG. 1 shows an example of a manufacturing apparatus of a multi-chambersystem in which all production processes are automated from a process offorming a first electrode to a sealing process.

The multi-chamber manufacturing apparatus shown in FIG. 1 includes:gates 100 a to 100 s; a take-out chamber 119; transfer chambers 104 a,102, 114, and 118; handing-over chambers 105 and 107; a preparationchamber 101; a first film forming chamber 106A; a second film formingchamber 106B; a third film forming chamber 106C; a fourth film formingchamber 106D; other film forming chambers 109 a, 109 b, 113 a, and 113b; process chambers 120 a and 120 b; setting chambers 126A, 126B, 126C,and 126D for installing an evaporation source; pre-treatment chambers103 a and 103 b; a first sealing chamber 116 a; a second sealing chamber116 b; a first stock chamber 130 a; a second stock chamber 130 b;cassette chambers 131 a and 131 b; a tray putting stage 121; and awashing chamber 122.

Hereinafter, a description will be made of a procedure for producing alight emitting device after a substrate to which a thin-film transistor,an anode (first electrode), and an insulator covering an end portion ofthe anode are formed in advance is loaded into the manufacturingapparatus shown in FIG. 1.

First, the above-mentioned substrate is set in the cassette chamber 131a or 131 b. If the substrate has a large size (for example, 300 mm×360mm), the substrate is set in the cassette chamber 131 a and 131 b. Ifthe substrate has a normal size (for example, 127 mm×127 mm), thesubstrate is transferred to the tray putting stage 121 and pluralsubstrates are set in a tray (having a size of, for example, 300 mm×360mm).

Next, the plural substrates each formed with the thin-film transistor,the anode, and the insulator covering an end portion of the anode aretransferred to the transfer chamber 118, and then further transferred tothe washing chamber 122 to remove impurities (such as fine particles)from the substrate surfaces by using a solution. If the substrates arewashed in the washing chamber 122, the substrates are set with thesurfaces to be formed with a film facing downward at the atmosphericpressure.

Also, before forming a film containing an organic compound, in order toremove moisture and gas from within the substrates, it is preferable toperform annealing for degasification in vacuum. Therefore, thesubstrates may be transferred to the pretreatment chambers 103 a and 103b each connected to the transfer chamber 118, to be subjected toannealing therein. Also, if a film containing an organic compound formedto an unnecessary portion is to be removed, the substrates aretransferred to the pretreatment chambers 103 a and 103 b to selectivelyremove a laminate of organic compound film layers. The pretreatmentchambers 103 a and 103 b each have plasma generating means, and generateplasma by exciting one or plural kinds of gas selected from the groupconsisting of Ar, H, F, and O, to thereby perform dry etching. Here, itis shown as an example that the two pretreatment chambers 103 a and 103b are provided to allow treatment on the two substrates substantially inparallel with each other.

Next, the substrates are transferred from the transfer chamber 118provided with a substrate transferring mechanism to the preparationchamber 101. In the manufacturing apparatus of this embodiment, thepreparation chamber 101 has a substrate inverting mechanism and caninvert the substrates appropriately. The preparation chamber 101 isconnected to a vacuum-exhaust process chamber and preferably set to theatmospheric pressure by introducing inert gas into the chamber after thechamber is vacuum-exhausted.

Next, the substrates are transferred to the transfer chamber 102connected to the preparation chamber 101. It is preferable that thetransfer chamber 102 be vacuum-exhausted in advance and maintain vacuumso as to contain as little moisture and oxygen as possible.

The above-mentioned vacuum-exhaust process chamber is provided with amagnetic levitation turbomolecular pump, a cryopump, or a dry pump. Thepump makes it possible for the transfer chamber connected to thepreparation chamber to reach a vacuum level of 10⁻⁵ to 10⁻⁶ Pa. Inaddition, reverse diffusion of impurities from the pump side and theexhaust system can be controlled. In order not to let impurities enterthe interior of the device, inert gas such as nitrogen or rare gas isintroduced. Used as the gas introduced into the device is one that isrefined to have a high purity by a gas refining machine prior tointroduction to the device interior. Thus, it is necessary to provide agas refining machine such that the gas is refined to have a high purityand, after that, introduced into an evaporation apparatus. Accordingly,oxygen, water, and other impurities are removed from within the gas inadvance, thereby making it possible to prevent those impurities fromentering the device interior.

Next, the substrates are transferred from the transfer chamber 102 tothe first forming chamber 106A, the second film forming chamber 106B,the third film forming chamber 106C, and the fourth film forming chamber106D. Then, low-molecular weight organic compound layers are formedwhich serve as hole injecting layers, hole transporting layers, andlight emitting layers.

As overall light emitting elements, organic compound layers exhibitingsingle-color (specifically white) light emission or full-color(specifically red, green, and blue) light emission can be formed. Here,an example will be described in which the organic compound layersexhibiting white light emission are formed in the respective filmforming chambers 106A, 106B, 106C, and 106D at the same time (each filmforming process is performed approximately in parallel).

Note that in the case where the organic compound layers exhibiting whitelight emission are a laminate of light emitting layers having differentlight emission colors, the organic compound layers are broadly dividedinto two types: a three wavelength type that includes the primary colorsof red, green, and blue and a two wavelength type that utilizes therelationship between complementary colors of blue and yellow orblue-green and orange. Here, an example will be described in which awhite light emitting element is obtained using the three wavelengthtype.

First, the respective film forming chambers 106A, 106B, 106C, and 106Dwill be described. The film forming chambers 106A, 106B, 106C, and 106Deach have movable evaporation source holders, which are prepared inplural numbers. In each of the film forming chambers, five evaporationsource holders are set in the following states: a first evaporationsource holder has aromatic diamine (referred to as TPD) for forming awhite light emitting layer sealed therein; a second evaporation sourceholder has p-EtTAZ for forming a white light emitting layer sealedtherein; a third evaporation source holder has Alq₃ for forming a whitelight emitting layer sealed therein; a fourth evaporation source holderhas an EL material sealed therein which is obtained by doping Alq₃ forforming a white light emitting layer with Nile Red that is a red lightemitting pigment; and a fifth evaporation source holder has Alq₃ sealedtherein.

It is preferable that EL materials be set in the above film formingchambers by using the following manufacturing system. That is, it ispreferable that a container (typically a melting pot) in which an ELmaterial is stored in advance by a material manufacturer be used to forma film. In addition, it is preferable that the container be set withoutbeing exposed to the atmosphere. Thus, it is preferable that the meltingpot be sealed in a second container when being shipped from the materialmanufacturer, and then be loaded into a film forming chamber whilemaintaining the sealed state. It is desirable that the setting chambers126A, 126B, 126C, and 126D each having vacuum-exhaust means andconnected to the film forming chambers 106A, 106B, 106C, and 106D,respectively, be set to vacuum or an inert gas atmosphere, and meltingpots be taken out of second containers in the setting chambers and thenbe set in the film forming chambers. As a result, a melting pot and anEL material stored in the melting pot can be protected fromcontamination. Note that metal masks may be stocked in the settingchambers 126A, 126B, 126C, and 126D.

Next, film forming steps will be described. In the film forming chamber106A, a mask is transferred from the setting chamber described above andset as the need arises. Then, the first to fifth evaporation sourceholders start to move sequentially to perform evaporation to thesubstrate. More specifically, TPD from the first evaporation sourceholder is sublimated by heating and is deposited by evaporation on theentire surface of the substrate. After that, p-EtTAZ from the secondevaporation source holder is sublimated, Alq₃ from the third evaporationsource holder is sublimated, Alq₃: Nile Red from the fourth evaporationsource holder is sublimated, and Alq₃ from the fifth evaporation sourceholder is sublimated, which are all deposited by evaporation on theentire surface of the substrate.

In the case of using an evaporation method, it is preferable to performevaporation in the film forming chamber that is vacuum-exhausted toreach a vacuum level of 5×10⁻³ Torr (0.665 Pa) or lower, preferably,10⁻⁴ to 10⁻⁶ Pa.

Note that the above-mentioned evaporation source holders with the ELmaterials set therein are provided in the respective film formingchambers, and also in the respective film forming chambers 106B to 106D,evaporation is performed in the same manner. In other words, the samefilm forming process can be performed to four substrates approximatelyin parallel. FIG. 7 shows a simple example of the path along which twoof the four substrates are processed. As a result, even if a given filmforming chamber is undergoing maintenance or cleaning, the film formingprocess is possible in the rest of the film forming chambers, therebyreducing the cycle time for the film formation. Accordingly, thethroughput of the light emitting device can be improved.

Next, the substrate is transferred from the transfer chamber 102 to thehanding-over chamber 105, and further transferred from the handing-overchamber 105 to the transfer chamber 104 a without being exposed to theatmosphere.

Next, a transfer mechanism set in the transfer chamber 104 a is used totransfer the substrate to the film forming chamber 109 a or the filmforming chamber 109 b, and then a cathode is formed to the substrate.The cathode may be formed by laminating two cathodes (lower layer andupper layer). The cathode (lower layer) is formed of an extremely thinmetal film (MgAg, MgIn, AlLi, CaN, or like other alloy film, or a filmformed by co-evaporation of aluminum and an element that belongs toGroup 1 or 2 in the periodic table) formed by evaporation usingresistance heating. The cathode (upper layer) is formed of a transparentconductive film (an indium tin oxide alloy (ITO) film, an indiumoxide-zinc oxide alloy (In₂O₃—ZnO) film a zinc oxide (ZnO) film, or thelike) formed by sputtering. Therefore, it is preferable that a filmforming chamber for forming a thin metal film be arranged in themanufacturing apparatus.

Through the above steps, a light emitting element having a laminatestructure as shown in FIGS. 17A and 17B is formed.

Next, without being exposed to the atmosphere, the substrate istransferred from the transfer chamber 104 a to the film forming chamber113 a or 113 b, and then a protective film consisting of a siliconnitride film or a silicon nitroxide film is formed to the substrate.Here, the film forming chambers 113 a and 113 b each include a silicontarget, a silicon oxide target, or a silicon nitride target. Forexample, a silicon nitride film can be formed by using the silicontarget and setting the atmosphere in the film forming chamber to anitrogen atmosphere or an atmosphere containing nitrogen and argon. FIG.1 shows an example system provided with the two film forming chambers113 a and 113 b such that a protective film can be formed to twosubstrates approximately in parallel.

Next, without being exposed to the atmosphere, the substrate formed witha light emitting device is transferred from the transfer chamber 104 ato the handing-over chamber 107, and further transferred from thehanding-over chamber 107 to the transfer chamber 114. Then, thesubstrate formed with a light emitting device is transferred from thetransfer chamber 114 to the first sealing chamber 116 a or the secondsealing chamber 116 b. Note that in the first sealing chamber 116 a andthe second sealing chamber 116 b, a sealing member for bondingsubstrates to each other later or for sealing a substrate is formed.FIG. 1 shows an example system provided with the two sealing chambers116 a and 116 b such that a bonding process can be performed to twosubstrates approximately in parallel.

A sealing substrate is set in the first stock chamber 130 a or thesecond stock chamber 130 b from the outside for preparation. Note thatin order to remove moisture and other impurities, it is preferable thatthe sealing substrate be subjected to annealing in vacuum in advance,for example, within the first stock chamber 130 a or the second stockchamber 130 b. If the sealing member for bonding the sealing substrateand the substrate on which the light emitting element is formed isformed on the sealing substrate, the sealing member is formed in thefirst stock chamber 130 a or the second stock chamber 130 b, and thesealing substrate on which the sealing member is formed is thentransferred to the first sealing chamber 116 a or the second sealingchamber 116 b. Note that the sealing substrate may be provided with adesiccant in the first sealing chamber 116 a or the second sealingchamber 116 b. Also, the first sealing chamber 130 a and the secondsealing chamber 130 b may be stocked with an evaporation mask to be usedat the time of evaporation.

Next, in order to perform degasification to the substrate provided withthe light emitting device, after performing annealing in vacuum or in aninert gas atmosphere, the sealing substrate provided with the sealingmember and the substrate formed with the light emitting device arebonded to each other. Also, an enclosed space is filled with nitrogen orinert gas. Note that here, the example of forming the sealing member onthe sealing substrate is shown. However, there is no particularlimitation and the sealing member may be formed on the substrate formedwith the light emitting element.

Next, the pair of bonded substrates are irradiated with UV light by a UVray irradiation mechanism provided in the sealing chamber 116 a, 116 bto thereby cure the sealing member. Note that a UV-curable and thermosetresin is used here as the sealing member. However, there is noparticular limitation as long as an adhesive is used as the sealingmember, and such a resin as one curable by only a UV ray may be used.

Further, instead of filling the enclosed space with inert gas, a resinmay be filled therein. In the case of a downward emission type, no lighttransmits through the cathode, so that the material for the resin to befilled are not particularly limited and the UV-curable resin or anopaque resin may be used. However, in the case of an upward emissiontype, a UV ray transmits through the cathode to cause damage to the ELlayer, so that the UV-curable resin cannot be used. Thus, in the case ofan upward emission type, it is preferable to use a transparent thermosetresin as the resin to be filled.

Next, the pair of bonded substrates are transferred from the sealingchamber 116 a, 116 b to the transfer chamber 114, and then transferredfrom the transfer chamber 114 to the take-out chamber 119 to be takenout thereof.

Further, after being taken out of the take-out chamber 119, the sealingmember is cured by heat treatment. In the case of using the upwardemission type and filling the enclosed space with the thermoset resin,the thermoset resin can be cured simultaneously with the heat treatmentfor curing the sealing member.

As described above, the use of the manufacturing apparatus shown in FIG.1 prevents a light emitting element from being exposed to the atmospherebefore the light emitting element is completely sealed in an enclosedspace. As a result, a light emitting device having high reliability canbe produced. Note that the transfer chamber 114 alternates betweenvacuum and a nitrogen atmosphere at the atmospheric pressure. However,it is desirable that the transfer chambers 102, 104 a, and 108 maintainvacuum all the time.

Note that, although not shown in the figures, a control drive unit isprovided which controls the path along which substrates are moved toindividual process chambers, to thereby realize a fully automaticsystem.

Also, it is possible to load a substrate formed with a transparentconductive film as the anode into the manufacturing apparatus shown inFIG. 1, and form a light emitting element (having a structure in whichlight emission caused in a layer containing an organic compound is takenout from the transparent anode toward a TFT; hereinafter referred to asdownward emission structure) that emits light in the direction oppositeto that of the laminate structure described above.

In the case where both the anode and the cathode are composed of atransparent or translucent material, it is also possible to form astructure in which light emission caused in the layer containing theorganic compound is taken out toward both the upper surface and thelower surface (hereinafter referred to as double-sided emissionstructure).

Further, FIG. 21 shows an example of a manufacturing apparatus providedwith two take-out chambers because plural take-out chambers becomenecessary in the case where elements are produced by simultaneouslyprocessing two substrates in different sizes in parallel. A mask stockchamber and a coating chamber are also provided in FIG. 21. Note that inFIG. 21, the same reference numerals as those in FIG. 1 are used.

In FIG. 21, reference numeral 100 t denotes a gate, 1003 the coatingchamber, 1013 the mask stock chamber, and reference numerals 1019 a and1019 b denote the take-out chambers.

Note that the mask stock chamber 1013 is stocked with evaporation masksto be used at the time of evaporation. The evaporation masks areappropriately transferred to each film forming chamber when performingevaporation, and then set therein. In particular, it is difficult tostock the mask having a large area in the setting chamber, so that it ispreferable to separately provide the mask stock chamber as shown in FIG.21. Also, the mask stock chamber 1013 may be stocked with not only theevaporation masks but also, for example, substrates.

Further, in the coating chamber 1003, a layer containing ahigh-molecular weight material may be formed by an ink jet method or aspin coating method. For example, an aqueous solution of poly(ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT/PSS) acting as a holeinjecting layer (an anode buffer layer), an aqueous solution ofpolyaniline/camphor sulfonic acid (PANI/CSA), PTPDES, Et-PTPDEK, PPBA orthe like may be coated over the entire surface of the first electrode(anode) and then subjected to baking.

Further, the PEDOT/PSS film formed by the spin coating method covers theentire surface. Accordingly, it is preferable to selectively removeportions of the film that cover end surfaces and perimeter of thesubstrate, a terminal portion, a region where a cathode and a lowerwiring are connected to each other, and the like. For example, it ispreferable that the removal is performed by O₂ ashing or the like usinga mask in the pretreatment chamber 103 a.

Embodiment 2

FIGS. 8A to 8C show a film forming system featured in moving a substrateand an evaporation source relative to each other. FIG. 8A is a sectionalview in X direction (a section taken along a dotted line A-A′), FIG. 8Bis a sectional view in Y direction (a section taken along a dotted lineB-B′) and FIG. 8C is a top view. Further, FIGS. 8A, 8B and 8C show theevaporation system in the midst of evaporation.

The film forming system shown in FIGS. 8A to 8C is characterized in thatin an evaporation system, an evaporation source holder installed with acontainer filled with an evaporation material is moved by a certainpitch relative to a substrate or the substrate is moved by a certainpitch relative to the evaporation source. Further, it is preferable tomove the evaporation source holder by a certain pitch to overlap ends(skirts) of a sublimated evaporation material.

Although a single or a plurality of the evaporation source holders maybe constituted, when the evaporation source holders are provided forrespective laminated films of EL layers, evaporation can be carried outefficiently and continuously. Further, a single or a plurality ofcontainers may be installed at the evaporation source holder and aplurality of containers filled with the same evaporation material may beinstalled. Further, when containers having different evaporationmaterials are arranged, a film can be formed at a substrate in a stateof mixing the sublimated evaporation materials (this is referred to ascommon evaporation).

In FIGS. 8A to 8C, a film forming chamber 11 includes a substrate holder12, an evaporation source holder 17 installed with an evaporationshutter 15, means for moving the evaporation source holder (notillustrated) and means for producing a low pressure atmosphere. Further,the film forming chamber 11 is installed with a substrate 13 and anevaporation mask 14. Further, alignment of the evaporation mask may beconfirmed by using a CCD camera (not illustrated). The evaporationsource holder 17 is installed with a container filled with anevaporation material 18. The film forming chamber 11 is vacuumed to avacuum degree of 5×10⁻³ Torr (0.665 Pa) or lower, preferably, 10⁻⁴through 10⁻⁶ Pa by the means for producing the low pressure atmosphere.

Further, in evaporation, the evaporation material is previouslysublimated (vaporized) by resistance heating and scattered in adirection of the substrate 13 by opening the shutter 15 in evaporation.An evaporated evaporation material 19 is scattered in an upwarddirection and is selectively vapor-deposited on the substrate 13 bypassing an opening portion provided at the evaporation mask 14. Further,preferably, a speed of film formation, a moving speed of the evaporationholder and opening and closing of the shutter are controlled by acontrol unit such as a personal computer. The evaporation rate of theevaporation source holder can be controlled by the moving speed.

Further, although not illustrated, evaporation can be carried out whilemeasuring a film thickness of a deposited film by a quartz oscillatorprovided at the film forming chamber 11. When the film thickness of thedeposited film is measured by using the quartz oscillator, a change inmass of a film deposited to the quartz oscillator can be measured as achange in the resonance frequency.

In the evaporation system shown in FIGS. 8A to 8C, in evaporation, adistance d of an interval between the substrate 13 and the evaporationsource holder 17 can be reduced to, representatively, 30 cm or smaller,preferably, 20 cm or smaller, further preferably, 5 cm through 15 cm tothereby significantly promote an efficiency of utilizing the evaporationmaterial and throughput.

In the evaporation system, the evaporation source holder 17 isconstituted by a container (representatively, crucible), a heaterarranged on an outer side of the container via a uniformly heatingmember, an insulating layer provided on an outer side of the heater, anouter cylinder containing these, a cooling pipe wound around an outerside of the outer cylinder and the evaporation shutter 15 for openingand closing an opening portion of the outer cylinder including anopening portion of a crucible. Further, the evaporation source holder 17may be a container capable of being carried in a state of fixing theheater to the container. Further, the container is formed by a materialof a sintered body of BN, a composite sintered body of BN and AlN,quartz or a graphite capable of withstanding high temperature, highpressure and low pressure.

Further, the evaporation source holder 17 is provided with a mechanismmovable in X direction or Y direction at inside of the film formingchamber 11 while maintaining a horizontal state. In this case, theevaporation source holder 17 is made to move in zigzag on atwo-dimensional plane as shown by FIG. 9A or FIG. 9B. Further, a pitchof moving the evaporation source holder 17 may pertinently be matched toan interval between insulators. Further, insulators 10 are arranged in astripe shape to cover end portions of first electrodes 21.

Further, in FIGS. 9A and 9B, timings of starting to move the evaporationsource holders A, B, C and D may be after stopping or before stoppingpreceding ones of the evaporation source holders. For example, withsetting an organic material capable of hole transporting at theevaporation holder A, an organic material serving as an light emittinglayer at the evaporation holder B, an organic material capable ofelectron transporting at the evaporation holder C and a material servingas a cathode buffer at the evaporation holder D, it is possible tocontinuously laminate these material layers in a same chamber. Further,when a succeeding one of the evaporation source holder starts movingbefore solidifying a vapor-deposited film, in an EL layer having alaminated layers structure, a region mixed with evaporation materials(mixed region) may be formed at an interface of respective films.

According to the invention of moving the substrate and the evaporationsource holders A, B, C and D relative to each other in this way,small-sized formation of the device can be achieved without needing toprolong a distance between the substrate and the evaporation sourceholder. Further, since the evaporation system is small-sized, adherenceof the sublimated evaporation material to the inner wall or theadherence preventive shield at inside of the film forming chamber isreduced and the evaporation material can be utilized without waste.Further, according to the evaporation method of the invention, it is notnecessary to rotate the substrate and therefore, the evaporation systemcapable of dealing with a large area substrate can be provided. Further,according to the invention of moving the evaporation source holder inthe X axis direction and the Y axis direction relative to the substrate,the vapor-deposited film can uniformly be formed.

Further, it is not necessarily needed that an organic compound providedat the evaporation source holder is one or one kind thereof but may be aplurality of kinds thereof. For example, other than one kind of amaterial provided as a luminescent organic compound at the evaporationsource holder, other organic compound which can be a dopant (dopantmaterial) may be provided along therewith. It is preferable to design anorganic compound layer to be vapor-deposited to constitute by a hostmaterial and a luminescent material (dopant material) having excitationenergy lower than that of the host material such that the excitationenergy of the dopant becomes lower than excitation energy of a holetransporting region and excitation energy of an electron transportinglayer. Thereby, diffusion of a molecular exciter of the dopant can beprevented and the dopant can effectively be made to emit light. Further,when the dopant is a material of a carrier trap type, an efficiency ofrecombining carriers can also be promoted. Further, the inventionincludes a case in which a material capable of converting tripletexcitation energy to luminescence is added to a mixing region as adopant. Further, in forming the mixing region, a concentration gradientmay be provided to the mixing region.

Further, when a plurality of organic compounds are provided at a singleevaporation source holder, it is preferable for evaporating directionsto be skew to intersect at a position of an object to be deposited suchthat the organic compounds are mixed together. Further, in order tocarry out common evaporation, the evaporation source holder may beprovided with four kinds of evaporation materials (for example, twokinds of host materials as evaporation material A, two kinds of dopantmaterials as evaporation material b). Further, when a pixel size issmall (or, an interval between respective insulators is narrow), a filmcan finely be formed by dividing inside of a container in four andcarrying out common evaporation for subjecting respective pertinently toevaporation.

Further, since the interval distance d between the substrate 13 and theevaporation source holder 17 is narrowed to, representatively, 30 cm orsmaller, preferably, 5 cm through 15 cm, there is a concern of heatingalso the evaporation mask 14. Therefore, it is preferable for theevaporation mask 14 to use a metal material having a low thermalexpansion rate which is difficult to deform by heat (for example, a highmelting point metal such as tungsten, tantalum, chromium, nickel ormolybdenum or an alloy including these elements, a material such asstainless steel, inconel, Hastelloy). For example, a low thermalexpansion alloy having 42% of nickel and 58% of iron or the like ispointed out. Further, in order to cool the evaporation mask to beheated, the evaporation mask may be provided with a mechanism ofcirculating a cooling medium (cooling water, cooling gas).

Further, in order to clean a deposited substance adhered to the mask, itis preferable to generate a plasma at inside of the film forming chamberby plasma generating means to vaporize the deposited substance adheredto the mask to vent the vapor to outside of the film forming chamber.For that purpose, a mask is separately provided with an electrode and ahigh frequency power source 20 is connected to either one of them.

Further, the film forming chamber includes gas introducing means forintroducing one kind or a plurality of kinds of gases selected from thegroup consisting of Ar, H, F, NF₃, and O and venting means for ventingthe deposited substance vaporized. By the above-described constitution,inside of the film forming chamber can be cleaned without being incontact with the atmosphere in maintenance.

Cleaning can be performed as follows, the atmosphere in a chamber issubstituted by nitrogen, and is vacuum exhausted, and a high frequencypower supply (13.56 MHz) can be connected with either the mask or theelectrode so that a plasma is generated the mask and the electrode (asubstrate shutter, not illustrated). Then, argon and hydrogen areintroduced to the chamber in respective flow rate of 30 sccm, and theatmosphere in the chamber are stabilized, an RF electric power of 800 Wis applied to generate a plasma, thereby the mask and inner wall of thechamber can be cleaned.

Further, the film forming chamber 11 is connected with a vacuumingchamber for vacuuming inside of the film forming chamber. The vacuumprocessing chamber is provided with a turbo-molecular pump of a magneticlevitation type, a cryopump or a dry pump. Thereby, the ultimate vacuumdegree of the film forming chamber 11 can be made to be 10⁻⁵ through10⁻⁶ Pa and inverse diffusion of an impurity from a pump side and anventing system can be controlled. In order to prevent an impurity frombeing introduced into the film forming chamber 11, as a gas to beintroduced, an inert gas of nitrogen or rare gas is used. There are usedthe gases to be introduced which are highly purified by a gas refinerbefore being introduced into the device. Therefore, it is necessary toprovide the gas refiner such that the gas is highly purified andthereafter introduced into the film forming chamber 11. Thereby, animpurity of oxygen, water or the like included in the gas can previouslybe removed and therefore, the impurities can be prevented from beingintroduced into the film forming chamber 11.

Further, the substrate holder 12 is provided with a permanent magnet forfixing the evaporation mask comprising a metal with the magnetic forceand also fixing the substrate 13 interposed therebetween. Although anexample of bringing the evaporation mask into close contact with thesubstrate 13 is shown here, a substrate holder or an evaporation maskholder fixed with an interval to some degree therebetween maypertinently be provided.

According to the film forming chamber having the mechanism of moving theevaporation source holder as described above, it is not necessary toprolong the distance between the substrate and the evaporation sourceholder and the evaporation film can uniformly be formed.

Embodiment 3

Here, a detailed description will be given of constitutions of acontainer for filling an evaporation material and an evaporation sourceholder at a surrounding thereof in reference to FIGS. 10A and 10B asfollows. Further, FIGS. 10A and 10B show a state of an open shutter.

FIG. 10A shows a sectional view of a surrounding of one containerinstalled at an evaporation source holder 304 illustrated with heatingmeans 303 provided at the evaporation source holder, a power source 307of the heating means, an evaporation material 302 of the container, afilter 305 provided at inside of the container and a shutter 306arranged above an opening portion provided at an upper portion of thecontainer. As the heating means 303, resistance heating, high frequencyor laser may be used, specifically, an electric coil may be used.

Further, the evaporation material 302 heated by the heating means 303 issublimated and the sublimated material 302 rises upwardly from theopening portion of the container. At this occasion, the sublimatedmaterial having a size equal to or larger than a certain constant amount(mesh of filter) cannot pass the filter 305 provided at inside of thecontainer, returns into the container and is sublimated again. Further,the filter 305 may be formed by a highly conductive material and heatedby heating means (not illustrated). By the heating, the evaporationmaterial can be prevented from being solidified and adhered to thefilter.

By the container having the constitution provided with such a filter,the evaporation material having an even size is vapor-deposited andtherefore, a speed of film formation can be controlled and a uniformfilm thickness can be provided and uniform evaporation withoutnonuniformity can be carried out. Naturally, when uniform evaporationwithout nonuniformity can be carried out, it is not necessarily neededto provide a filter. Further, a shape of the container is not limited tothat in FIG. 10A.

Next, an explanation will be given of a container filled with anevaporation material having a constitution different from that of FIG.10A in reference to FIG. 10B.

FIG. 10B is illustrated with a container 311 installed at an evaporationholder, an evaporation material 312 at inside of the container, firstheating means 313 provided at the evaporation source holder, a powersource 318 of the first heating means, a shutter 317 arranged above anopening portion of the container, a plate 316 provided above the openingportion, second heating means 314 provided to surround the filter and apower source 319 of second heating means.

Further, the evaporation material 312 heated by the first heating means313 is sublimated and the sublimated evaporation material rises upwardlyfrom the opening portion of the container 311. At this occasion, thesublimated material having a size equal to or larger than a certainconstant amount cannot pass an interval between the plate 316 providedabove the opening portion of the container and the second heating means314, impinges on the plate 316 and returns to inside of the container.Further, since the plate 316 is heated by the second heating means 314,the evaporation material can be prevented from solidifying and adheringto the plate 316. Further, it is preferable to form the plate 316 by ahighly conductive material. Further, a filter may be provided in placeof the plate.

Further, as heating temperature (T₁) by the first heating means 313, atemperature higher than a sublimating temperature (T_(A)) of theevaporation material is applied, a heating temperature (T₂) by thesecond heating means 314 may be lower than that of the first heatingmeans. This is because once sublimated evaporation material is easy tosublimate and therefore, the evaporation material is sublimated withoutapplying the actual sublimating temperature. That is, respective heatingtemperatures may establish T₁>>T₂>T_(A).

By such a container having a constitution of providing the heating meansaround the plate, the evaporation material having an even size issublimated, further, the sublimated material passes a vicinity of theheating means and therefore, adherence of the evaporation material tothe plate is reduced, further, the speed of film formation can becontrolled and therefore a uniform film thickness can be provided anduniform evaporation without nonuniformity can be carried out. Naturally,when the uniform evaporation without nonuniformity can be carried out,it is not necessarily needed to provide the plate. Further, the shape ofthe container is not limited to those in FIGS. 10A and 10B but, forexample, the container may be provided with shapes as shown by FIGS. 11Aand 11B.

FIG. 11A shows an example of providing heating means 402 at anevaporation source holder 404 illustrating sectional views of examplesof shapes of containers 403 and 405 in each of which an opening portionof the container is narrowed toward an upper side thereof. Further,after filling a refined evaporation material in a container having awide opening portion, the shapes of the container 403 or 405 shown inFIG. 11A may be constituted by using a lid or the like. Further, when adiameter of the opening portion of the container narrowed toward theupper side is constituted by the size of the evaporation materialintended to form, an effect similar to that of a filter can be achieved.

Further, FIG. 11B shows examples of providing heating means 412 atcontainers. Although shapes of the containers 413 and 415 are similar tothose of FIG. 11A, the heating means 412 are provided at the containersper se. Further, power sources of the heating means may be designed tobe brought into an ON state at a stage of being installed to evaporationsource holders. By such a constitution of providing the heating means atthe container per se, heat can be applied sufficiently to an evaporationmaterial even in the case of a container having an opening portion in ashape which is difficult to heat.

Next, a specific constitution of an evaporation source holder will beexplained in reference to FIGS. 12A and 12B. FIGS. 12A and 12B showenlarged views of evaporation source holders.

FIG. 12A shows a constitution example of providing four containers 501filled with an evaporation material to an evaporation source holder 502in a shape of a lattice and providing shutters 503 above the respectivecontainers and FIG. 12B shows a constitution example of providing fourcontainers 511 filled with an evaporation material to an evaporationsource holder 512 in a linear shape and providing shutters 513 above therespective containers.

A plurality of the containers 501 or 511 filled with the same materialmay be installed at the evaporation source holder 502 or 512 illustratedin FIG. 12A or 12B or a single one of the container may be installed atthe evaporation source holder. Further, common evaporation may becarried out by installing containers filled with different evaporationmaterials (for example, host material and guest material). Further, asdescribed above, the evaporation material is sublimated by heating thecontainer and a film is formed at the substrate.

Further, as shown by FIG. 12A or 12B, it may be controlled whether thefilm is formed by the sublimated evaporation material by providing theshutter 503 or 513 above each container. Further, only a single one ofthe shutter may be provided above all of the containers. Further, by theshutter, it can be reduced to sublimate and scatter an unnecessaryevaporation material without stopping to heat the evaporation sourceholder which does not form the film, that is, the evaporation sourceholder being at standby. Further, the constitution of the evaporationsource holder is not limited to those of FIGS. 12A and 12B but maypertinently be designed by a person for embodying the invention.

By the above-described evaporation source holder and container, theevaporation material can efficiently be sublimated, further, the film isformed in a state in which the size of the evaporation material is evenand therefore, a uniform evaporation film without nonuniformity isformed. Further, a plurality of evaporation materials can be installedat the evaporation source holder and therefore, common evaporation caneasily be carried out. Further, an aimed EL layer can be formed in oneoperation without moving the film forming chamber for each film of theEL layer.

Embodiment 4

An explanation will be given, with reference to FIG. 13, of a system ofa fabricating method of filling a refined evaporation material in theabove-described container, carrying the container and thereafterinstalling the container directly at an evaporation system which is afilm forming device, to carry out evaporation.

FIG. 13 illustrates a manufacturer, representatively, a materialmanufacturer 618 (representatively, material manufacturer) for producingand refining an organic compound material which is an evaporationmaterial and a manufacturer (representatively, production factory) 619of a luminescent device which is a manufacturer of a luminescent devicehaving an evaporation system.

First, an order 610 is carried out from the luminescent devicemanufacturer 619 to the material manufacturer 618. Based on the order610, the material manufacturer 618 refines to sublimate an evaporationmaterial and fills an evaporation material 612 in a shape of a powderrefined in high purity to a first container 611. Thereafter, thematerial manufacturer 618 isolates the first container from theatmosphere such that an extra impurity is not adhered to inside oroutside thereof, and contains the first container 611 in secondcontainers 621 a and 621 b to hermetically seal for preventing the firstcontainer 611 from being contaminated at inside of the clean environmentchamber. In hermetically sealing the second containers 621 a and 621 b,at inside of the containers it is preferable to be vacuum or to befilled with an inert gas of nitrogen or the like. Further, it ispreferable to clean the first container 611 and the second containers621 a and 621 b before refining or containing the evaporation material612 with an ultra high purity. Further, although the second containers621 a and 621 b may be package films having barrier performance forblocking oxygen or moisture from mixing thereinto, in order to be ableto take out the containers automatically, it is preferable that thesecond containers are constituted by stout containers having lightblocking performance in a shape of a cylinder or a shape of a box.

Thereafter, the first container 611 is carried (617) from the materialmanufacturer 618 to the luminescent device manufacturer 619 in a stateof being hermetically sealed by the second containers 621 a and 621 b.

At the luminescent device manufacturer 619, the first container 611 isdirectly introduced into a vacuumable processing chamber 613 in a stateof being hermetically sealed in the second containers 621 a and 621 b.Further, the processing chamber 613 is an evaporation system installedwith heating means 614 and substrate holding means (not illustrated) atinside thereof.

Thereafter, inside of the processing chamber 613 is vacuumed to bringabout a clean state in which oxygen or moisture is reduced as less aspossible, thereafter, without breaking the vacuum, the first container611 is taken out from the second containers 621 a and 621 b, the firstcontainer 611 is installed in contact with the heating means 614 and anevaporation source can be prepared. Further, an object to be deposited(here, substrate) 615 is installed at the processing chamber 613 to beopposed to the first container 611.

Successively, an evaporation film 616 is formed on a surface of theobject to be deposited 615 by applying heat to the evaporation materialby the heating means 614. The evaporation film 616 provided in this waydoes not include an impurity and when a luminescent element is finishedby using the evaporation film 616, high reliability and high brightnesscan be realized.

Further, after forming the film, the evaporation material remaining atthe first container 611 may be sublimated to refine at the luminescentdevice manufacturer 619. After forming the film, the first container 611is installed at the second containers 621 a and 621 b, taken out fromthe processing chamber 613 and carried to a refining chamber forsublimating to refine the evaporation material. There, the remainingevaporation material is sublimated to refine and the evaporationmaterial in a shape of a powder refined at high purity is filled into aseparate container. Thereafter, in a state of being hermetically sealedin the second container, the evaporation material is carried to theprocessing chamber 613 to carry out evaporation processing. At thisoccasion, it is preferable that a relationship among temperature (T3)for refining the remaining evaporation material, temperature (T4)elevated at a surrounding of the evaporation material and temperature(T5) at a surrounding of the evaporation material which is sublimated torefine satisfy T3>T4>T5. That is, in the case of sublimating to refinethe material, when temperature is lowered toward a side of the containerfor filling the evaporation material to be sublimated to refine,convection is brought about and the material can be sublimated to refineefficiently. Further, the refining chamber for sublimating to refine theevaporation material may be provided in contact with the processingchamber 613 and the evaporation material which has been sublimated torefine may be carried without using the second container forhermetically sealing the evaporation material.

As described above, the first container 611 is installed in theevaporation chamber which is the processing chamber 613 without beingbrought into contact with the atmosphere at all to enable to carry outevaporation while maintaining the purity at the stage of containing theevaporation material 612 by the material manufacturer. Therefore,according to the invention, a fully automated fabricating systempromoting the throughput can be realized and an integrated closed systemcapable of avoiding the impurity from mixing to the evaporation material812 refined at the material manufacturer 618 can be realized. Further,the evaporation material 612 is directly contained in the firstcontainer 611 by the material matter based on the order and therefore,only a necessary amount thereof is provided to the luminescent devicemanufacturer and the comparatively expensive evaporation material canefficiently be used. Further, the first container and the secondcontainer can be reutilized to amount to a reduction in cost.

A specific explanation will be given of a mode of the container to becarried in reference to FIG. 14 as follows. A second container dividedinto an upper portion (621 a) and a lower portion (621 b) used fortransportation includes fixing means 706 provided at an upper portion ofthe second container for fixing a first container, a spring 705 forpressing the fixing means, a gas introducing port 708 provided at alower portion of the second container for constituting a gas path formaintaining the second container being depressurized, an O ring 707 forfixing the upper container 621 a and the lower container 621 b and aretaining piece 702. The first container 611 filled with the refinedevaporation material is installed in the second container. Further, thesecond container may be formed by a material including stainless steeland the first container may be formed by a material including titanium.

At the material manufacturer, the refined evaporation material is filledin the first container 611. Further, the upper portion 621 a and thelower portion 621 b of the second container are matched via the O ring707, the upper container 621 a and the lower container 621 b are fixedby the retaining piece 702, and the first container 611 is hermeticallysealed at inside of the second container. Thereafter, inside of thesecond container is depressurized via the gas introducing port 708 andis replaced by a nitrogen atmosphere and the first container 611 isfixed by the fixing means 706 by adjusting the spring 705. A desiccantmay be installed at inside of the second container. When inside of thesecond container is maintained in vacuum, in a low pressure or innitrogen atmosphere in this way, even a small amount of oxygen or watercan be prevented from adhering to the evaporation material.

The first container 611 is carried to the luminescent devicemanufacturer 619 under the state and is directly installed to theprocessing chamber 613. Thereafter, the evaporation material issublimated by heating and the evaporation film 616 is formed.

Next, an explanation will be given of a mechanism of installing thefirst container 611 which is carried by being hermetically sealed in thesecond container to a film forming chamber 806 in reference to FIGS. 15Aand 15B and FIGS. 16A and 16B. Further, FIGS. 15A and 15B and FIGS. 16Aand 16B show the first container in the midst of transportation.

FIG. 15A illustrates to a top view of an installing chamber 805including a base 804 for mounting the first container or the secondcontainer, an evaporation source holder 803, and carrying means 802 forcarrying the base 804, the evaporation source holder 803 and the firstcontainer, and FIG. 15B illustrates a perspective view of the installingchamber. Further, the installing chamber 805 is arranged to becontiguous to the film forming chamber 806 and the atmosphere of theinstalling chamber can be controlled by means for controlling theatmosphere via a gas introducing port. Further, the carrying means ofthe invention is not limited to a constitution of pinching a side faceof the first container to carry as illustrated in FIGS. 15A and 15B butmay be constructed by a constitution of pinching (picking) the firstcontainer at upper part thereof to carry.

The second container is arranged to such an installing chamber 805 abovethe base 804 in a state of disengaging the retaining piece 702.Successively, inside of the installing chamber 805 is brought into adecompressed state by means for controlling the atmosphere. Whenpressure at inside of the installing chamber and pressure at inside ofthe second container become equal to each other, there is brought abouta state of being capable of opening the second container easily.Further, the upper portion 621 a of the second container is removed andthe first container 611 is installed in the evaporation source holder803 by the carrying means 802. Further, although not illustrated, aportion for installing the removed upper portion 621 a is pertinentlyprovided. Further, the evaporation source holder 803 is moved from theinstalling chamber 805 to the film forming chamber 806.

Thereafter, by heating means provided at the evaporation source holder803, the evaporation material is sublimated and the film starts to beformed. In forming the film, when a shutter (not illustrated) providedat the evaporation source holder 803 is opened, the sublimatedevaporation material is scattered to the direction of the substrate andthe vapor-deposited onto the substrate to form the luminescent layer(including hole transporting layer, hole injecting layer, electrontransporting layer and electron injecting layer).

Further, after finishing evaporation, the evaporation source holder 803returns to the installing chamber 805 and the first container 611installed at the evaporation source holder 803 by the carrying means 802is transferred to the lower container (not illustrated) of the secondcontainer installed at the base 804 and is hermetically sealed by theupper container 621 a. At this occasion, it is preferable that the firstcontainer, the upper container 621 a and the lower container arehermetically sealed by a combination by which the containers have beencarried. Under the state, the installing chamber 805 is brought underthe atmospheric pressure and the second container is taken out from theinstalling chamber, fixed with the retaining piece 702 and is carried tothe material manufacturer 618.

Next, an explanation will be given of a mechanism of installing aplurality of first containers carried by being hermetically sealed bythe second containers to a plurality of the evaporation source holders,which is different from those of FIGS. 15A and 15B in reference to FIGS.16A and 16B.

FIG. 16A illustrates a top view of an installing chamber 905 including abase 904 for mounting the first container or the second container, aplurality of evaporation source holders 903, a plurality of carryingmeans 902 for carrying the first containers and a rotating base 907 andFIG. 16B illustrates a perspective view of the installing chamber 905.Further, the installing chamber 905 is arranged to be contiguous to afilm forming chamber 906 and the atmosphere of the installing chambercan be controlled by means for controlling the atmosphere via a gasintroducing port.

By the rotating base 907 and the plurality of carrying means 902,operation of installing the plurality of first containers 611 to theplurality of evaporation source holders 903 and transferring theplurality of first containers 611 from the plurality of evaporationsource holders finished with film formation to the base 904 canefficiently be carried out. At this occasion, it is preferable toinstall the first container 611 to the second container which has beencarried.

Further, in order to carry the evaporation source holder for startingevaporation and the evaporation source holder finished with evaporationefficiently, the rotating base 907 may be provided with a rotatingfunction. In addition, the structure of the rotating base 907 is notlimited to the above one, as far as the rotating base 907 has a functionof moving to the right and lift directions, when the rotating baseapproaches to the evaporation holders arranged in the film formingchamber 906, a plurality of the first containers may be provided at theevaporation holders by the carrying means 902

According to an evaporation film formed by the above-describedevaporation system, an impurity can be reduced to an extreme and when aluminescent element is finished by using the evaporation film, highreliability and brightness can be realized. Further, by such afabricating system, the container filled by the material manufacturercan be installed directly to the evaporation system and therefore,oxygen or water can be prevented from adhering to the evaporationmaterial and further ultrahigh purity formation of the luminescentelement in the future can be dealt with. Further, by refining thecontainer having the remaining evaporation material again, waste of thematerial can be eliminated. Further, the first container and the secondcontainer can be reutilized and the low cost formation can be realized.

The present invention constituted by the above structure will bedescribed in more detail with examples shown below.

EXAMPLES

Examples of the present invention are described thereinafter based onthe drawings. In addition, in all drawings used for the description ofthe examples, same portions are given common symbols, and the repetitivedescriptions thereof are omitted.

Example 1

In this example, an example of forming TFT on a substrate having aninsulating surface and forming an EL element (light emitting element) isshown in FIG. 17. A cross-sectional view of one TFT that is connected toan EL element in a pixel portion is shown in this example.

A base insulating film 201 is formed by a lamination of insulating filmssuch as a silicon oxide film, a silicon nitride film or a siliconoxynitride film on a substrate 200 having an insulating surface.Although the base insulating film 201 herein uses a two-layer structure,it may use a structure having a single layer or two layers or more ofthe insulating films. The first layer of the base insulating film is asilicon oxynitride film formed to have a thickness of 10 to 200 nm(preferably 50 to 100 nm) by plasma CVD using a reaction gas of SiH₄,NH₃ and N₂O. Herein, a silicon oxynitride film is formed (compositionratio: Si=32%, O=27%, N=24% and H=17%) having a film thickness of 50 nm.The second layer of the base insulating film is a silicon oxynitridefilm formed to have a thickness 50 to 200 nm (preferably 100 to 150 nm)by plasma CVD using a reaction gas of SiH₄ and N₂O. Herein, a siliconoxynitride film is formed (composition ratio: Si=32%, O=59%, N=7% andH=2%) having a film thickness of 100 nm.

Subsequently, a semiconductor layer is formed on the base insulatingfilm 201. The semiconductor layer is formed as follows: an amorphoussemiconductor film is formed by known means (a sputtering, an LPCVD, aplasma CVD, or the like), then, the film is crystallized by a knowncrystallization method (a laser crystallization method, a thermalcrystallization method or a thermal crystallization method using acatalyst such as nickel), and then, the crystalline semiconductor filmis patterned into a desired form. This semiconductor layer is formed ina thickness of 25 to 80 nm (preferably 30 to 60 nm). The material of thecrystalline semiconductor film, although not limited in material, ispreferably formed of silicon or a silicon-germanium alloy.

In the case of forming a crystalline semiconductor film by a lasercrystallizing process, it is possible to use an excimer laser of apulse-oscillation or continuous-oscillation type, a YAG laser, or anYVO₄ laser. In the case of using such laser, preferably used is a methodthat the laser light emitted from a laser oscillator is condensed by anoptical system into a linear form to be irradiated onto thesemiconductor film. The condition of crystallization is to beappropriately selected by those who implement the invention. In the caseof using an excimer laser, pulse oscillation frequency is 30 Hz andlaser energy density is 100 to 400 mJ/cm² (typically 200 to 300 mJ/cm²).Meanwhile, in the case of using a YAG laser, preferably its secondharmonic is used and pulse oscillation frequency is 1 to 10 kHz andlaser energy density is 300 to 600 mJ/cm² (typically 350 to 500 mJ/cm²).The laser light focused linear to a width of 100 to 1000 μm, e.g. 400μm, is irradiated throughout the substrate entirety, whereupon theoverlap ratio of linear laser beam may be taken 50 to 98%.

Then, the surface of the semiconductor layer is cleaned by an etchantcontaining a hydrogen fluoride, to form a gate insulating film 202covering the semiconductor layer. The gate insulating film 202 is formedby an insulating film containing silicon having a thickness of 40 to 150nm by the use of plasma CVD or sputtering. In this example, a siliconoxynitride film is formed (composition ratio: Si=32%, O=59%, N=7% andH=2%) to have a thickness of 115 nm by plasma CVD. Of course, the gateinsulating film 202 is not limited to a silicon oxynitride film but maybe made in a single layer or a lamination of layers of insulating filmscontaining other form of silicon.

After cleaning the surface of the gate insulating film 202, a gateelectrode 210 is formed.

Then, a p-type providing impurity element (such as B), herein, adequateamounts of boron is added to the semiconductor to form a source region211 and a drain region 212. After the addition of the impurity element,heating process, intense light radiation or laser irradiation is made inorder to activate the impurity element. Simultaneously with activation,restoration is possible from the plasma damage to the gate insulatingfilm or from the plasma damage at the interface between the gateinsulating film and the semiconductor layer. Particularly, it isextremely effective to irradiate the second harmonic of a YAG laser at amain or back surface thereby activating the impurity element in anatmosphere at room temperature to 300° C. YAG laser is preferableactivating means since it requires a few maintenances.

In the subsequent process, after hydrogenation is carried out, aninsulator 213 a made from an organic or inorganic material (for example,from a photosensitive organic resin) is formed, then, an aluminumnitride film, an aluminum oxynitride film shown as AlN_(x)O_(y), or afirst protection film 213 b made from a silicon nitride film are formed.The film shown as AlN_(x)O_(y) is formed by introducing oxygen,nitrogen, or rear gas from the gas inlet system by RF sputtering using atarget made of AlN or Al. The content of nitrogen in the AlN_(x)O_(y)film may be in the range of at least several atom %, or 2.5 to 47.5 atom%, and the content of oxygen may be in the range of at most 47.5 atom %,preferably, less than 0.01 to 20 atom %. A contact hole is formedtherein reaching the source region 211 or drain region 212. Next, asource electrode (wiring) 215 and a drain electrode 214 are formed tocomplete a TFT (p-channel TFT). This TFT will control the current thatis supplied to OLED (Organic Light Emitting Device).

Also, the present invention is not limited to the TFT structure of thisexample, but, if required, may be in a lightly doped drain (LDD)structure having an LDD region between the channel region and the drainregion (or source region). This structure is formed with a region animpurity element is added with light concentration between the channelformation region and the source or drain region formed by adding animpurity element with high concentration, which is called an LDD region.Furthermore, it may be in, what is called, a GOLD (Gate-drain OverlappedLDD) structure arranging an LDD region overlapped with a gate electrodethrough a gate insulating film. It is preferable that the gate electrodeis formed in a lamination structure and etched to have a different taperangle of an upper gate electrode and a lower gate electrode to form anLDD region and a GOLD region in a self-aligning manner using the gateelectrode as a mask.

Meanwhile, although explanation herein was by using the p-channel TFT,it is needless to say that an n-channel TFT can be formed by using ann-type impurity element (P, As, etc.) in place of the p-type impurityelement.

Though a top gate TFT is described as an example in this example, thepresent invention can be applied irrespective of TFT's structure. Forexample, the present invention can be applied to a bottom gate (reversestagger) TFT and a forward stagger TFT.

Subsequently, in the pixel portion, a first electrode 217 in contactwith a connecting electrode in contact with the drain region is arrangedin matrix shape. This first electrode 217 serves as an anode or acathode of the light-emitting element. Then, an insulator (generallyreferred to as a bank, a partition, a barrier, a mound, or the like) 216that covers the end portion of the first electrode 217 is formed. Forthe insulator 216, a photosensitive organic resin is used. In the caseof using a negative type photosensitive acrylic resin is used as amaterial of the insulator 216, for example, the insulator 216 may bepreferably prepared such that the upper end portion of the insulator 216has a curved surface having a first curvature radius and the lower endportion of the insulator has a curved surface having a second curvatureradius. Each of the first and second curvature radiuses may bepreferably in the range of 0.2 μm to 3 μm. Furthermore, a layer 218containing an organic compound is formed in the pixel portion, and asecond electrode 219 is then formed thereon to complete an EL element.This second electrode 219 serves as a cathode or an anode of the ELelement.

The insulator 216 that covers the end portion of the first electrode 217may be covered with a second protective film formed of an aluminumnitride film, an aluminum nitride oxide film, or a silicon nitride film.

For instance, an example of using a positive type photosensitive acrylicresin as a material of the insulator 216 is shown in FIG. 17B. Theinsulator 316 a has a curved surface having a curvature radius only theupper end thereof. Furthermore, the insulator 316 a is covered with asecond protective film 316 b formed of an aluminum nitride film, analuminum nitride oxide film, or a silicon nitride film.

For instance, when the first electrode 217 is used as an anode, thematerial of the first electrode 217 may be a metal (i.e., Pt, Cr, W, Ni,Zn, Sn, or In) having a large work function. The end portion of such anelectrode 217 is covered with the insulator (generally referred to as abank, a partition, a barrier, a mound, or the like) 216 or 316, then, avacuum-evaporation is carried out moving an evaporation source alongwith the insulator 216 or 316 by using the evaporation system shown inEmbodiments 1 to 3. For example, a film forming chamber isvacuum-exhausted until the degree of vacuum reaches 5×10⁻³ Torr (0.665Pa) or less, preferably 10⁻⁴ to 10⁻⁶ Pa, for vacuum-evaporation. Priorto vacuum-evaporation, the organic compound is vaporized by resistanceheating. The vaporized organic compound is scattered on the substrate asthe shutter is opened for vacuum-evaporation. The vaporized organiccompound is scattered upward, then, deposited on the substrate throughan opening formed in a metal mask. A light emitting layer (including ahole transporting layer, a hole injection layer, an electrontransporting layer, and an electron injection layer) is formed.

In the case that a layer containing an organic compound is formed thatemits white luminescence in its entirety by vacuum-evaporation, it canbe formed by depositing each light emitting layer. For instance, an Alq₃film, an Alq₃ film partially doped with Nile red which is a red lightemitting pigment, a p-EtTAZ film, and a TPD (aromatic diamine) film arelayered in this order to obtain white light.

In case of using vacuum-evaporation, as shown in Embodiment 3, acontainer (typically a melting pot) in which an EL material that avacuum-evaporation material is stored in advance by a materialmanufacturer is set in a film forming chamber. Preferably, the meltingpot is set in the film forming chamber while avoiding contact with theair. The melting pot shipped from a material manufacturer is preferablysealed in a second container during shipment and is introduced into afilm forming chamber in that state. Desirably, a chamber having vacuumexhaust means is connected to the film forming chamber, the melting potis taken out of the second container in vacuum or in an inert gasatmosphere in this chamber, and then the melting pot is set in the filmforming chamber. In this way, the melting pot and the EL material storedin the melting pot are protected from contamination.

The second electrode 219 comprises a laminate structure of a metal(e.g., Li, Mg, or Cs) having a small work function; and a transparentconductive film (made of an indium tin oxide (ITO) alloy, an indium zincoxide alloy (In₂O₃—ZnO), zinc oxide (ZnO), or the like) on the thinfilm. For attaining a low-resistance cathode, an auxiliary electrode maybe provided on the insulator 216 or 316. The light-emitting element thusobtained emits white luminescence. Here, the example in which the layer218 containing the organic compound is formed by vacuum-evaporation hasbeen described. According to the present invention, however, it is notlimited to a specific method and the layer 218 may be formed using acoating method (a spin coating method, an ink jet method).

In this example, an example of depositing layers made from low molecularmaterial as an organic compound layer is described though, both highmolecular materials and low molecular materials may also be deposited.

It can be thought that there are two types of structures of an activematrix light emitting device having TFT in terms of radiating directionof luminescence. One is a structure that luminescence generated in alight emitting element can be observed passing through the secondelectrode, and can be manufactured using the above-mentioned steps.

Another structure is that luminescence generated in the light emittingelement is irradiated into the eyes of the observer after passingthrough the first electrode, it is preferable that the first electrode217 may be prepared using a material having a translucency. Forinstance, when the first electrode 217 is provided as an anode, atransparent conductive film (made of an indium tin oxide (ITO) alloy, anindium zinc oxide alloy (In₂O₃—ZnO), zinc oxide (ZnO), or the like) isused for a material of the first electrode 217 and the end portionthereof is covered with the insulator (generally referred to as a bank,a partition, a barrier, a mound, or the like) 216, followed by formingthe layer 218 containing an organic compound. On this layer,furthermore, a second electrode 219 formed of a metal film (i.e., analloy of MgAg, MgIn, AlLi, CaF₂, CaN, or the like, or a film formed by aco-vacuum-evaporation of an element of Group I and Group II in theperiodic table and aluminum) is formed as a cathode. Here, a resistiveheating method using vacuum-evaporation is used for the formation of acathode, so that the cathode can be selectively formed using avacuum-evaporation mask.

After forming the second electrode 219 by the steps described above, aseal substrate is laminated using a sealing material to encapsulate thelight-emitting element formed on the substrate 200.

Here, an appearance view of an active matrix type light-emitting deviceis described with reference to FIGS. 18A and 18B. Further, FIG. 18A is atop view showing the light emitting apparatus and FIG. 18B is asectional view constituted by cutting FIG. 18A by a line A-A′. A sourcesignal side driving circuit 1101, a pixel portion 1102, and a gatesignal line driving circuit 1103 are formed on a substrate 1110. Aninner side surrounded by a seal substrate 1104, the sealing material1105, and the substrate 1110 constitutes a space 1107.

Further, a wiring 1108 for transmitting signals inputted to the sourcesignal side driving circuit 1101 and the gate signal side drivingcircuit 1103 receives a video signal or a clock signal from FPC(flexible printed circuit) 1109 for constituting an external inputterminal. Although only FPC is illustrated here, the FPC may be attachedwith a printed wiring substrate (PWB). The light emitting apparatus inthe specification includes not only a main body of the light emittingapparatus but also a state in which FPC or PWB is attached thereto.

Next, a sectional structure will be explained in reference to FIG. 18B.Driver circuits and the pixel portion are formed over a substrate 1110and here, the source signal line driving circuit 1101 as the drivercircuit and the pixel portion 1102 are shown.

Further, the source signal line driving circuit 1101 is formed with aCMOS circuit combined with an n-channel type TFT 1123 and a p-channeltype TFT 1124. Further, TFT for forming the driver circuit may be formedby a publicly-known CMOS circuit, PMOS circuit or NMOS circuit. Further,although according to this example, a driver integrated type formed withthe driver circuits over the substrate is shown, the driver integratedtype is not necessarily be needed and the driver circuits can be formednot over the substrate but at outside thereof.

Further, the pixel portion 1102 is formed of a plurality of pixels eachincluding a switching TFT 1111, a current controlling TFT 1112, and afirst electrode (anode) 1113 electrically connected to a drain of thecurrent controlling TFT 1112.

Further, an insulating layer 1114 is formed at both ends of the firstelectrode (anode) 1113 and an organic compound layer 1115 is formed onthe first electrode (anode) 1113. The organic compound layer 1115 isformed by moving an evaporation source along with the insulating film1114 by using the device shown in Embodiments 1 and 2. Further, a secondelectrode (cathode) 1116 is formed over the organic compound layer 1115.As a result, a light-emitting element 1118 comprising the firstelectrode (anode) 1112, the organic compound layer 1115 and the secondelectrode (cathode) 1116 is formed. Here, the light-emitting element1118 shows an example of white color luminescence and therefore,provided with the color filter comprising a coloring layer 1131 and alight-shielding layer 1132 (for simplification, overcoat layer is notillustrated here).

In FIGS. 19A to 19C, a color filter is formed at the side of a sealsubstrate 1104 since it is the structure that light emitted from a lightemitting element is observed through the second electrode, however, incase of the structure that light emitted from a light emitting elementis observed through the first electrode, a color filter is formed at theside of the substrate 1110.

The second electrode (cathode) 1116 functions also as a wiring common toall the pixels and electrically connected to FPC 1109 via the connectionwiring 1108. The third electrode (auxiliary electrode) 1117 is formed onthe insulating layer 1114 to realize to make the second electrode have alow resistance.

Further, in order to encapsulate the light-emitting element 1118 formedover the substrate 1110, the seal substrate 1104 is pasted by thesealing material 1105. Further, a spacer comprising a resin film may beprovided for ensuring an interval between the seal substrate 1104 andthe light-emitting element 1118. Further, the space 1107 on the innerside of the sealing material 1105 is filled with an inert gas ofnitrogen or the like. Further, it is preferable to use epoxy speciesresin for the sealing material 1105. Further, it is preferable that thesealing material 1105 is a material for permeating moisture or oxygen asless as possible. Further, the inner portion of the space 1107 may beincluded with the substance having an effect of absorbing oxygen ormoisture.

Further, according to the example, as a material for constituting theseal substrate 1104, other than glass substrate or quartz substrate, aplastic substrate comprising FRP (Fiberglass-Reinforced Plastics), PVF(polyvinyl fluoride), Mylar, polyester or acrylic resin can be used.Further, it is possible to adhere the seal substrate 1104 by using thesealing material 1105 and thereafter seal to cover a side face (exposedface) by a sealing material.

By encapsulating the light-emitting element as described above, thelight-emitting element can completely be blocked from outside and asubstance for expediting to deteriorate the organic compound layer suchas moisture or oxygen can be prevented from invading from outside.Therefore, the highly reliable light-emitting device can be provided.

Further, this example can be freely combined with Embodiments 1 to 4.

Example 2

Given as examples of electronic apparatuses that employ the lightemitting device manufactured in accordance with the present inventionare video cameras, digital cameras, goggle type displays (head mounteddisplays), navigation systems, audio reproducing devices (such as caraudio and audio components), laptop computers, game machines, portableinformation terminals (such as mobile computers, cellular phones,portable game machines, and electronic books), and image reproducingdevices equipped with recording media (specifically, devices with adisplay device that can reproduce data in a recording medium such as adigital versatile disk (DVD) to display an image of the data). A wideviewing angle is important particularly for portable informationterminals because their screens are often slanted when they are lookedat. Therefore it is preferable for portable information terminals toemploy the light emitting device using the light emitting element.Specific examples of these electronic apparatuses are shown in FIGS. 20Ato 20H.

FIG. 20A shows a light emitting device including a case 2001, a supportbase 2002, a display unit 2003, speaker units 2004, a video inputterminal 2005, etc. The light emitting device manufactured in accordancewith the present invention can be applied to the display unit 2003. Inaddition, the light emitting device shown in FIG. 20A can be completedby the present invention. Since the light emitting device having thelight emitting element is of self-luminous type, the device does notneed a backlight and can make a thinner display unit than that of aliquid crystal display device. The light emitting device refers to alllight emitting devices for displaying information, including ones forpersonal computers, for TV broadcasting reception, and foradvertisement.

FIG. 20B shows a digital still camera including a main body 2101, adisplay unit 2102, an image receiving unit 2103, operation keys 2104, anexternal connection port 2105, a shutter 2106, etc. The light emittingdevice manufactured in accordance with the present invention can beapplied to the display unit 2102. The digital camera shown in FIG. 16Bcan be completed by the present invention.

FIG. 20C shows a laptop computer including a main body 2201, a case2202, a display unit 2203, a keyboard 2204, an external connection port2205, a pointing mouse 2206, etc. The light emitting device manufacturedin accordance with the present invention can be applied to the displayunit 2203. The laptop computer shown in FIG. 20C can be completed by thepresent invention.

FIG. 20D shows a mobile computer including a main body 2301, a displayunit 2302, a switch 2303, operation keys 2304, an infrared port 2305,etc. The light emitting device manufactured in accordance with thepresent invention can be applied to the display unit 2302. The mobilecomputer shown in FIG. 20D can be completed by the present invention.

FIG. 20E shows a portable image reproducing device equipped with arecording medium (a DVD player, to be specific). The device includes amain body 2401, a case 2402, a display unit A 2403, a display unit B2404, a recording medium (DVD or the like) reading unit 2405, operationkeys 2406, speaker units 2407, etc. The display unit A 2403 mainlydisplays image information whereas the display unit B 2404 mainlydisplays text information. The light emitting device manufactured inaccordance with the present invention can be applied to the displayunits A 2403 and B 2404. The image reproducing device equipped with arecording medium also includes home-video game machines. The DVD playershown in FIG. 20E can be completed by the present invention.

FIG. 20F shows a goggle type display (head mounted display) including amain body 2501, display units 2502, and arm units 2503. The lightemitting device manufactured in accordance with the present inventioncan be applied to the display units 2502. The goggle type display shownin FIG. 20F can be completed by the present invention.

FIG. 20G shows a video camera including a main body 2601, a display unit2602, a case 2603, an external connection port 2604, a remote controlreceiving unit 2605, an image receiving unit 2606, a battery 2607, anaudio input unit 2608, operation keys 2609 etc. The light emittingdevice manufactured in accordance with the present invention can beapplied to the display unit 2602. The video camera shown in FIG. 20G canbe completed by the present invention.

FIG. 20H shows a cellular phone including a main body 2701, a case 2702,a display unit 2703, an audio input unit 2704, an audio output unit2705, operation keys 2706, an external connection port 2707, an antenna2708, etc. The light emitting device manufactured in accordance with thepresent invention can be applied to the display unit 2703. If thedisplay unit 2703 displays white letters on a black background, thecellular phone consumes less power. The cellular phone shown in FIG. 20Hcan be completed by the present invention.

If a brighter luminance of luminescence materials becomes valuable inthe future, the light emitting device can be used in front or rearprojectors by enlarging outputted light that contains image informationthrough a lens or the like and projecting the light.

These electronic apparatuses now display with increasing frequencyinformation sent through electronic communication lines such as theInternet and CATV (cable television), especially, animation information.Since the luminescence materials have very fast response speed, thelight emitting device is suitable for moving images.

According to the present invention, there can be provided amanufacturing apparatus including the plural film forming chambers forperforming the evaporation process, which are arranged in a row.Accordingly, the film forming processes are performed in the plural filmforming chambers approximately in parallel, thereby improving thethroughput of the light emitting device and allowing the reduction of aprocessing time per substrate.

Further, according to the present invention, even though the processingnumber of substrates is slightly reduced, the maintenance of one orplural film forming chambers is possible without temporarily stoppingthe production line.

1. A method of fabricating light emitting devices by using anevaporation system including a plurality of first deposition chambersfor forming a film of an organic compound layer and a plurality ofsecond deposition chambers for forming a conductive film, said methodcomprising the steps of: forming a first organic compound layer over afirst substrate in one of the plurality of first deposition chambers;forming a second organic compound layer over a second substrate inanother of the plurality of first deposition chambers; after forming thefirst organic compound layer, moving the first substrate from the one ofthe plurality of first deposition chambers to one of the plurality ofsecond deposition chamber by using a carrying means without beingexposed to an atmosphere; moving the second substrate from the anotherof the plurality of first deposition chambers to another of theplurality of second deposition chambers by using the carrying meanswithout being exposed to an atmosphere after the first substrate ismoved from the one of the plurality of first deposition chambers;forming a first conductive film in contact with the first organiccompound layer in the one of the plurality of second depositionchambers; and forming a second conductive film in contact with thesecond organic compound layer in the another of the plurality of seconddeposition chambers, wherein the first organic compound layer and thesecond organic compound layer are formed approximately in parallel. 2.The method of fabricating light emitting devices according to claim 1,wherein the first conductive film and the second conductive film areformed approximately in parallel.
 3. The method of fabricating lightemitting devices according to claim 1, wherein the first organiccompound layer comprises a first hole transporting layer, a first lightemitting layer and a first electron transporting layer, and wherein thesecond organic compound layer comprises a second hole transportinglayer, a second light emitting layer and a second electron transportinglayer.
 4. The method of fabricating light emitting devices according toclaim 3, wherein each of the first light emitting layer and the secondlight emitting layer is formed by laminating a plurality of layers whichemit different colors.
 5. The method of fabricating light emittingdevices according to claim 3, wherein each of the first light emittinglayer and the second light emitting layer is formed by laminating afirst layer which emits blue on a second layer which emits yellow. 6.The method of fabricating light emitting devices according to claim 3,wherein each of the first light emitting layer and the second lightemitting layer emits white light.
 7. A method of fabricating lightemitting devices by using an evaporation system including a plurality offirst deposition chambers for forming a film of an organic compoundlayer, a plurality of second deposition chambers for forming aconductive film and a plurality of third deposition chambers for forminga protective film, said method comprising the steps of: forming a firstorganic compound layer over a first substrate in one of the plurality offirst deposition chambers; forming a second organic compound layer overa second substrate in another of the plurality of first depositionchambers; after forming the first organic compound layer, moving thefirst substrate from the one of the plurality of first depositionchambers to one of the plurality of second deposition chambers by usinga first carrying means without being exposed to an atmosphere; movingthe second substrate from the another of the plurality of firstdeposition chambers to another of the plurality of second depositionchambers by using the first carrying means without being exposed to anatmosphere after the first substrate is moved from the one of theplurality of first deposition chambers; forming a first conductive filmin contact with the first organic compound layer in the one of theplurality of second deposition chambers; forming a second conductivefilm in contact with the second organic compound layer in the another ofthe plurality of second deposition chambers; moving the first substratefrom the one of the plurality of second deposition chambers to one ofthe plurality of third deposition chambers by using a second carryingmeans without being exposed to an atmosphere after the first conductivefilm is formed; moving the second substrate from the another of theplurality of second deposition chambers to another of the plurality ofthird deposition chambers by using the second carrying means withoutbeing exposed to an atmosphere after the first substrate is moved fromthe one of the plurality of second deposition chambers to the one of theplurality of third deposition chambers; forming a first protective filmover the first conductive film in the one of the plurality of thirddeposition chambers; and forming a second protective film over thesecond conductive film in the another of the plurality of thirddeposition chambers, wherein the first organic compound layer and thesecond organic compound layer are formed approximately in parallel, andwherein the first conductive film and the second conductive film areformed approximately in parallel.
 8. The method of fabricating lightemitting devices according to claim 7, wherein the first protective filmand the second protective film are formed approximately in parallel. 9.The method of fabricating light emitting devices according to claim 7,wherein the first organic compound layer comprises a first holetransporting layer, a first light emitting layer and a first electrontransporting layer, and wherein the second organic compound layercomprises a second hole transporting layer, a second light emittinglayer and a second electron transporting layer.
 10. The method offabricating light emitting devices according to claim 9, wherein each ofthe first light emitting layer and the second light emitting layer isformed by laminating a plurality of layers which emit different colors.11. The method of fabricating light emitting devices according to claim7, wherein each of the first light emitting layer and the second lightemitting layer is formed by laminating a first layer which emits blue ona second layer which emits yellow.
 12. The method of fabricating lightemitting devices according to claim 9, wherein each of the first lightemitting layer and the second light emitting layer emits white light.